Coronary Artery Bypass Surgery Helpful During Long-Term for Children With Kawasaki Disease CME
News Author: Laurie Barclay, MD
CME Author: Charles P. Vega, MD, FAAFP
CME Released: 07/07/2009; Valid for credit through 07/07/2010
July 7, 2009 — Coronary artery bypass graft (CABG) surgery offers long-term benefits for children with cardiovascular complications of Kawasaki disease (KD), according to the results of a study reported in the June 22 Online First issue of Circulation.
"The long-term outcome of pediatric coronary artery bypass for patients with severe inflammatory coronary sequelae secondary to Kawasaki disease is unknown," write Soichiro Kitamura, MD, from the National Cardiovascular Center in Osaka, Japan, and colleagues. "We describe the long-term outcome of...114 patients after their surgery for KD coronary complications, presently the world's most common cause of pediatric coronary artery disease."
This case series consisted of 114 children and adolescents aged 1 to 19 years (median age, 10 years) when undergoing CABG. Median follow-up was 19 years (maximum, 25 years). The mean number of distal anastomoses per patient was 1.7 ± 0.8. The internal thoracic artery was used in all but 3 patients, most frequently for left anterior descending artery stenosis, whereas 24 patients had saphenous vein grafting, primarily for lesions affecting other arteries. Coronary and graft statuses were evaluated with multiple angiograms.
There were no operative or in-hospital deaths. All 5 deaths occurring during follow-up were cardiac in origin. Survival rates at 20 and 25 years were 95% (95% confidence interval [CI], 88% - 98%). Cardiac event-free rates were 67% at 20 years and 60% at 25 years (95% CI, 46% - 72%). The most prevalent events were percutaneous coronary intervention and reoperation. Although 88 patients (77%) continued to receive medications, all 109 survivors are currently asymptomatic when performing their daily activities.
At 20 years, the overall graft patency rate was 87% (95% CI, 78% - 93%) for internal thoracic artery grafts (n = 154) and 44% (95% CI, 26% - 61%) for saphenous vein grafts (n = 30; P < .001). For non–left anterior descending artery lesions, patency was also significantly better for arterial grafts (87%; 95% CI, 73% - 94%; n = 59) vs saphenous vein grafts (42%; 95% CI, 23% - 60%; n = 27; P = .002).
"Although the 25-year survival was excellent after pediatric coronary bypass for Kawasaki disease, the event-free rate declined progressively," the study authors write. "This reality mandated continued follow-up. Reinterventions successfully managed most cardiac events."
Limitations of this study include observational design and possible selection bias.
"An internal thoracic artery [ITA] graft was the most favorable for children," the study authors conclude. "Pediatric coronary bypass surgery with the use of the ITA should be an established treatment for severe coronary disease due to KD."
In an accompanying editorial, Brian W. McCrindle, MD, MPH, from The Hospital for Sick Children, Toronto, Ontario, Canada, notes that most patients with KD will be expected to survive into adulthood.
"Successful transition to adult care is an important issue," Dr. McCrindle writes. "Outcomes must be tracked seamlessly into adulthood if ongoing concerns about prognosis are to be resolved. In the meantime, advocacy for healthy lifestyle and screening and management of cardiovascular risk factors for all patients is prudent and recommended."
The study authors and Dr. McCrindle have disclosed no relevant financial relationships.
Circulation. Published online June 22, 2009.
Clinical Context
KD can have severe clinical consequences that extend into adulthood, and an editorial by McCrindle, which accompanies the current article, provides a review of KD. Although the incidence of KD is 20 to 25 per 100,000 children younger than 5 years in North America, it is 7 to 8 times more common in Japan. Coronary artery aneurysms are a major complication of KD, occurring in approximately one quarter of patients. However, when KD is treated appropriately with intravenous immunoglobulin, the rate of aneurysm formation is closer to 4%. KD can also promote cardiac valvulitis and myocarditis.
Some children with severe abnormalities of the coronary arteries require CABG, but the long-term outcomes of this surgery are largely unknown. The current study reports on outcomes decades after surgery in patients with a history of KD.
Study Highlights
114 children and adolescents younger than 20 years underwent CABG for inflammatory coronary obstructive lesions associated with KD. The median age of subjects at the time of the operation was 10 years, and 25% of subjects were girls. A total of 45% of subjects experienced KD during the first year of life.
Approximately one third of the study cohort had experienced a previous myocardial infarction, and 14% had a left ventricular ejection fraction less than 50% before CABG.
The median duration of the time from acute illness with KD to CABG was 6 years.
The number of distal anastomoses per patient was 1.7, and all but 3 subjects received grafts using the internal thoracic artery. The most frequent site of anastomosis was the left anterior descending artery.
The current study describes outcomes at a median follow-up duration of 19 years after CABG.
There were no operative or hospital deaths. The 20- and 25-year survival rates were 95%.
All 5 recorded deaths were among patients with a history of reduced left ventricular ejection fraction.
Among survivors, no patient required a heart transplant.
Cardiac events occurred in 29% of subjects during follow-up. The most common event by far was the need for postoperative coronary interventions. A total of 15% of all participants underwent percutaneous coronary intervention, and 8% had reoperation involving the coronary vessels.
Percutaneous coronary interventions were performed at a mean of 9 years after the original CABG.
The mean postoperative left ventricular ejection fraction was 55%.
Only 23% of patients did not receive regular medications at the time of their last follow-up visit.
41% of surviving patients were permitted to perform in all physical activities by their cardiologist. All 109 survivors were symptom-free in their daily activities.
The 20-year graft patency rates for internal thoracic artery and saphenous vein grafts were 87% and 44%, respectively.
Clinical Implications
KD is more common in Japan vs North America. The rate of coronary aneurysm formation in KD can be 25%, but appropriate treatment with intravenous immunoglobulin dramatically reduces the formation of coronary aneurysms. KD can also promote cardiac valvulitis and myocarditis.
In the current study, the 25-year survival rate after CABG for KD was 95%, and most patients had good physical function. However, most patients also required treatment with long-term medications, and the overall rate of cardiac events during follow-up was 29%.